This does align the chain, but unfortunately, that doesn't mean the rear wheel is aligned with the front wheel, which is much more important. However, I'd be interested to see how close the f & r wheels are to being aligned after just aligning the chain.
if the chain is aligned then the rear wheel is straight as the rear sprocket and front sprocket need to be aligned.(so must be aligned with front wheel) I know the method of using string etc to align the rear wheel with the front is also a good tool to use. I just find this to be a good guide. I would like to try a laser as this tool you need to really be level at the top of it.
